It is known that a geolocation can be carried out through a communication between a client device (the object to be located) and a centralized server (the system geolocating the object such as a geostationary satellite). The GPS system works in this manner.
However, in the context of locating men and equipments in a mobile limited area, while data exchanges with the outside are forbidden, a system including a centralized server does not meet the constraints of the previously-mentioned problem.
Furthermore, centralizing the location system involves transmitting a signal according to a star-shaped structure (transmission of a signal between each object to be located and the location server). Such a transmission structure requires to solve problems related to the existence of obstacles that may hinder or prevent the signal transmission between an object to be located and the server.
In addition, the data transmission in a star-shaped structure requires the presence of the server for relaying data between the objects to be located, when each of them requires to know the relative position of their counterparts in the limited area. The location system based on a GPS-type exchange between the client and the server does not meet this need when the context prohibits any exchange with a point outside the limited area containing all the objects to be located.
Traditional GPS-type location systems for example imperfectly allow the location of two points having the same latitude and longitude but having different altitudes, making it difficult to locate two objects having the same coordinates, for example on different floors of a building.